Interchangeable
by Insidiously
Summary: Castiel wakes up emptied of the souls he had devoured. The angel has no recollection of how he got there... or why he was suddenly trapped in Sam Winchester's body. To either of his sides the Winchesters souls have found new homes. /Post S6 Finale.


_**Disclaimer: **__I do not own Supernatural, Castiel or Sam and Dean Winchester, sadly. Nor am I in anyway affiliated with them. Though I like to pretend._

**So, I have had this idea floating around in my mind since the Season 6 finale… I thought it would make a pretty great multi-chapter story that could incorporate some drama, some humor and hell, maybe a little romance if I am feeling particularly sassy one day. And I have finally gotten around to writing it! If you guys would be interested in hearing of the adventures of Sammy!Dean, Cas!Sam and Dean!Cas then please, leave me a review. I will love you forever.**

**"Interchangeable" – **_**A Supernatural Story**_

The knowledge came as a surprise for Castiel. He had awoken dreary that night, as if he had been dragged deep underwater and had suddenly been tossed to the surface. The angel's memory was a fog. And he was awake.

It had been nearly four months since the angel had consumed the souls of purgatory. He had swallowed them without hesitation, sure that his own weighted powers would be enough to keep him in full control of his conscious… but he was wrong. The hazy, half formed memories in his mind were enough to tell him that. Castiel could remember the violence mainly. The feeling of need that came with each and every being he tortured just because he could. The demon Crowley's face formed in the forefront of his mind, smirking as always but this time covered in blood so thick that the liquid almost looked black. Cas closed his eyes… What had he done?

Beside him a being stirred but in the darkness of whatever room he was in made it unable for the angel was unable to make out any shape. "Hello?" His voice croaked, sounding tinny and unlike his own. Castiel assumed he had gone too long without liquid upon his vocal chords. The angel cleared his throat and tried the word again expecting no result but a quick kick to his side alerted him to the fact that he really was not alone. There were at least two other beings in the place with him.

"Sammy?" An eerily familiar voice mumbled and Cas felt his brow furrow. He reached out in front of him, swiping at the ground with his hand until his fingers fell upon something solid. Something that kicked out again. Castiel snapped his hand back to his torso at once and shook his head. Human and, judging by the question and hostile kick, the stranger was most likely Dean Winchester. The angel let out a deep sigh – he didn't particularly feel like dealing with the Winchesters at this current moment in time. Not after being lost in himself for months on end, unable to control the hunger for power that had dwelled inside of him. Castiel lay back on the ground.

By his feet the other individual stirred again and within a few moments Cas could make out muted footsteps along the concrete floor. Whoever had been lying below him was up and about, hopefully searching for some sort of switch that would shed some light into the room. "I think I can feel a switch." Dean's voice calls from a few feet away. So Cas had been correct in thinking that the eldest Winchester was present. Which meant that the man now beside him had to be Sam. Castiel grabbed at the man who had kicked him before and wrapped a hand around his ankle, tugging slightly.

"Sam, it is Castiel." He says, still surprised by the state of his tone. The leg jolts out violently.

"Back the hell off, dude." The being calls and again Cas pulls a face. Something was wrong here… That was not Sam speaking. But then-

Castiel's thoughts were cut off by the blinding light that then radiated though the room. The angel closed his eyes in an attempt to keep his brain from accepting the fluorescent too quickly and within a few moments Cas was able to peak out of the slits of his eyelids. Dean was standing over him with wide eyes and an utterly shocked look on his face. A look of almost terror. Castiel couldn't help but feel a ping of annoyance in the back of his skull. He had just, after all, regurgitated thousands upon thousands of souls – of course he wasn't going to be looking very pleasing to the eye currently but he was near certain he didn't deserve that kind of look.

The angel pushes to his rear and glares silently at Dean before turning to see who was to his left. As his eyes settled on the figure that was still lying on his back he could feel his jaw drop.

In front of him stood Castiel.

Well, not Castiel, really, as he was the angel… But the body that Cas had been wearing for years, the body that Jimmy Novak had bravely sacrificed for the greater good. And right now it was lying limp and wearing an expression fit to kill as he gazed at Dean. Castiel didn't know what to say and as he busied himself with trying to figure out his first words his vessel spoke first.

"What the FUCK?" It breathed, voice only a notch below frantic yelling. Dean's eyes went from their staring at Castiel to the vessel on the ground beside the angel.

"…Dean?" Dean himself asked and Castiel's vessel nodded feverishly. Cas' mind was working in circles. Finally, it struck him and he held his own hands out in front of him, flexing the fingers as his eyes trailed along the entirety of his current vessel. These were not his hands, not his wrists, his arms… The trench-coat was gone, instead covering the body of the man on the left. The man who Castiel had just come to realize was Dean. Cas' eyes turned to the Dean look-alike that was hovering over him and he blinked.

"Sam?" Castiel asked and the figure nodded, looking thoroughly weirded out. Castiel felt his head spin. That would leave him with…

The angel stood to his feet at once, rushing over to the far wall of the blank, dank room in which the trio was currently situated in and began frantically scrubbing at the age stained mirror that resided there. Within a few moments a reflection had made itself know and Castiel stared into it. Sam Winchester met his gaze back. A large lump rose at the back of Cas' throat before he turned back to the Winchesters. Both were staring at him.

"Castiel?" Sam ventured, sounding particularly odd using Dean's low, drawling voice. The angel nodded and Sam closed his eyes. Dean, however, was busy stripping himself of the angel's trademark jacket.

"What is this, Cas?" Dean muttered, running his hands along the suit that Castiel's former vessel was wearing. Cas stood speechless. "What the hell happened?"


End file.
